1. Field of the Invention
The present invention relates to an image processing apparatus useful for supporting a revision workflow which allows a plurality of operators to add information to a document to be printed and revise the document.
2. Description of the Related Art
Conventionally, a number of workflow systems that support processing of a document such as a form when the document is circulated to a plurality of processing persons in an office are being developed.
If the circulated document is in electronic data, the processing person can revise the electronic data on a screen of a personal computer (PC). If the electronic data is revised on a PC, since the history of the person who made the revision and the revised portion remains, it is easy to track the revision data from the history information.
However, since a document using a paper medium is easier-to-see and easier-to-handle for the processing persons compared to electronic data, even if a processing person receives the document in electronic data, in some cases, the person prints the document on a paper medium and manually adds information to the paper medium or correct the data printed on the paper medium. In such a case, it is necessary to extract difference information, which is the information manually added to the paper medium, and manage the difference information in association with the original data.
Japanese Patent Application Laid-Open No. 2004-246577 discusses a method for extracting information added to data by comparing the original data with the information-added data, and synthesizing the difference information with the original data. Japanese Patent Application Laid-Open No. 2004-246577 also discusses a method for determining a portion where the difference is determined with respect to the original document by vectorizing the extracted difference information.
In a case where a paper medium with the synthesized difference information is passed on to operators one after another, there may be a case where it is desirable to change processing from the predetermined workflow depending on the difference information.
An example of such a case is where processing is changed according to content of a form. If the processing of the form is to be changed according to its content, it is useful to use a system that embeds workflow information in a paper medium being a medium of the original data, and change the configuration of the workflow when additional information is added to the paper medium. Such a system is discussed in Japanese Patent Application Laid-Open No. 2006-243830.
However, if the circulated document is a specification sheet or a manual, many people will be involved in the task of the revision. In such a case, since paper is easier-to-see and easier-to-handle, it is easily assumed that a person that received the document in electronic data prints the document, manually corrects it, and passes the document on to the next person.
If the system discussed in Japanese Patent Application Laid-Open No. 2004-246577 or Japanese Patent Application Laid-Open No. 2006-243830 is adopted and such revision workflow is applied, however, the problem described below may occur.
According to the method discussed in Japanese Patent Application Laid-Open No. 2004-246577, original information is embedded in advance. When the first processing person prints, adds information, and scans the document, the image processing apparatus compares the input image and the original image. Then, the first processing person passes the scan data on to the second processing person. The second processing person adds information and passes the data on to the third processing person in a similar manner, and this process is repeated. In this case, the extracted difference information includes not only the information added by the previous processing person but also the information added by the first processing person. In other words, the extracted information is always the difference between the original data and the input image. Thus, difference information generated by each processing person cannot be extracted.
Further, according to the method discussed in Japanese Patent Application Laid-Open No. 2006-243830, the workflow is changed according to what the processing person has written and not where the processing person has written. Thus, even if a difference is generated by a plurality of processing persons at a same area, the workflow is not changed.
Consequently, when a document is revised by workflow processing according to the system discussed in Japanese Patent Application Laid-Open No. 2004-246577 or Japanese Patent Application Laid-Open No. 2006-243830, after a processing person added information to a certain area, even if another processing person makes revision to the same area, it is not possible to know the fact that information has been added to the document and the content of the information which has been added.